10 July, 1919. | Ornatucntdl Australian Flora. 



423 



the ground they continue to breed the insects, which, when fully 

 developed, infest the next crop of flower buds. 



The leaf miner is another serious pest, and it is specially affecting 

 the Willow wattle (Acacia saligna), Acacia prominens, and the Mount 

 Morgan wattle (Acacia podylarioe folia). A small fly lays her eggs 

 under the epidermis of the leaves. From the eggs are hatched very 

 small caterpillars, w^hich eat the substance of the leaves under the 

 outer skin, mining and tunnelling them, and making the tree very 

 unsightly, and ere long the foliage drops off. This pest also attacks 

 such garden plants as sunflowers, marguerite-daisies, and cinerarias; 

 and also the common weeds, sow or milk thistle, and the English dande- 

 lion. To minimize the plague, the weeds should be kept in check, and 

 immediately after each flowering season the affected bushes or trees 

 should be well pinined, cutting off all the parts attacked, and burning 

 them at once. Then the pruned plants should be sprayed with any 

 benzine or benzole emulsions, or with tar or phenyle waters. 



Sometimes brown rusty-looking galls appear on the wattles in the 

 form of large irregular swellings. These are the results of attacks of 

 gall-making rusts, and the galls should be cut off and burned. 



Should any leaf-eating insect attack the foliage, the tree may be 

 sprayed with a weak solution of arsenate of lead. 



Considerable trouble and damage axe ex- 

 perienced in South Africa as a result of at- 

 tacks on wattles by the caterpillars of the 

 " bagm^orm.'' There are species of bagwomis 

 here, as well as allied forms of stick case 

 moths, and it is possible that these pests may 

 do serious harm to the wattles in the future. 

 A pest that occasionally does damage to 

 wattles in Australia is the larvae of the fire 

 blight beetle of the wattle, Paropsis 

 orphana. Large plantations of black and 

 silver wattles, which were grown for the 

 bark, have been killed by this pest, which 

 works very rapidly. 



African experiences with the bagworm, 

 which, like the fire blight beetle, attacks the 

 foliage, have shown that the best means ol 

 combating it is by means of " dust-spray- 

 ing." Dust-sip raying is in vogue in ximerioa, 

 and special machines are used for the pur- 

 pose. The dusts used were: — (a) Paris 

 green and lime, 1 in 10; and (h) arsenate 

 of lead and lime, 1 in 20. The powder was 

 applied at the rate of 100 lbs. per acre, and 

 an even distribution killed from 70 to 76 per 

 cent, of the larvae. The trees then recovered 

 quickly. Thus the dust spray, on large areas, 

 Cootamundra Wattle, after may prove very valuable for all leaf-eating 

 cutting hard back. pests. 



